Second batch on top of first yeast cake

[firejim]

I have a batch of AIH Bluemoon clone going right now. I am thinking about ordering a basic summer wheat extract kit and brewing on the current yeast cake?

The few questions I have are

1) is this just a bad idea?
2) Should I rack the Blue Moon after a week to secondary or wait 2 weeks, cold crash it and the reuse the cake?
3) Do you reuse all the cake or pull some out and only use some?
4) Is this worth the $7 saving of not buying a new pack?

Thank you for the help/

 

[boydster]

1) Not at all
2) Either way works, but if rack to secondary you could be harvesting just the most flocculent and lowest attenuating yeast from the primary (depends on your fermentation whether this is true or not)
3) You probably only need about 1/4 of the yeast cake, assuming you are brewing batches with a similar OG
4) I reuse yeast often, it helps cut down on the total cost per batch. Practice good sanitation and you should be able to harvest and reuse yeast several times without worry about off-flavors or contamination.

I just harvested some US-05 from a carboy today, and I have it split up into 4 jars. Each jar is enough to make another brew with, and then I can harvest again from each new brew. If you reuse it right away, you'll have very high viability. If you store it, keep it in the fridge. If I store it longer than 2 weeks, I usually make a starter with it.

 

[firejim]

I am fermenting at 73 +/- .3 , would you rack?

Is it better to let it stay in the primary and cold crash to clear?

What's best for the yeast ?


Sent from my iPad using Home Brew

 

[boydster]

What kind of yeast? The temp is on the warm side for most ale yeast.

The yeast doesn't care either way. I think it's better for the beer to leave it in primary - no chance of oxidizing or infecting it during a transfer.

 

[firejim]

I used a Wyeast smack pack - 3944 Belgian wheat yeart.

It is going crazy in the box witha STC-1000 set at 21.5c.

This is only my 4 batch and I have racked the other 3 batchs.

If I don't rack, how long should a leave it in the carboy before I bottle?

 

[sandyeggoxj]

That yeast temp range is 62-75*F or 16-24*C. You are at the high end of the temp range. That could produce some off flavors. I am not familiar with the yeast strain so I can't tell you for sure.

 

[morticaixavier]

I used a Wyeast smack pack - 3944 Belgian wheat yeart.

It is going crazy in the box witha STC-1000 set at 21.5c.

This is only my 4 batch and I have racked the other 3 batchs.

If I don't rack, how long should a leave it in the carboy before I bottle?

Leave it till the gravity is stable. so two readings 3 or so days apart are the same.

Check out http://www.mrmalty.com/calc/calc.html

for a repitching calculator that will tell you pretty accurately how much of that slurry to use. It's not a huge savings when you are brewing two beers of similar gravity but if you start getting into big high alchohol beers it can really make a difference. It's hard to get enough yeast together to ferment say a 1.120 barley wine but if you brew a 1.038 ordinary bitter first you've essentially made a 5 gallon starter.

 

[boydster]

Let your hydrometer be your guide. Once your gravity is stable for 2 readings over a 3+ day span, it will be ready to package.

 

[JimRausch]

I have a batch of AIH Bluemoon clone going right now. I am thinking about ordering a basic summer wheat extract kit and brewing on the current yeast cake?

The few questions I have are

1) is this just a bad idea?
2) Should I rack the Blue Moon after a week to secondary or wait 2 weeks, cold crash it and the reuse the cake?
3) Do you reuse all the cake or pull some out and only use some?
4) Is this worth the $7 saving of not buying a new pack?

Thank you for the help/

I reuse yeast fairly often. Definitely use the Mr. Malty site to check out how much slurry to use. However, my general procedure is, after I rack to a bottling bucket, I add 2-3 qt. of boiled then cooled water, swirl well to mix, then pour the slurry into sanitized qt. mason jars. Into fridge to let it settle. At repitching time, I decant, then pitch 1 jar for SGs under 1.060, 2 jars for over 1.060, and 3-4 for lagers. This way I can get 2-3 batches out of one smackpack. (Could get more but then I'm usually on to different style/different strain).